Sorbent products such as mats, wipes, socks, and booms are commonly used to absorb fluids. These sorbent products are frequently used in industrial facilities and may be placed in an area where a leak or spill is occurring or may be anticipated. For example, sorbent products can be placed around equipment or attached to equipment or pipes. Apart from the industrial applications, sorbent products are also applicable for cleaning up more routine spills in facilities like grocery stores, hospitals, and schools.
Melt-blown polypropylene (MBPP) sorbents are widely used as they are durable, inexpensive and readily collect liquid spills. Compared to alternatives, such as clay granules, MBPP sorbents are clean (e.g., non-dusting) and easy to use. MBPP sorbents without further modifying additives are naturally oleophilic, meaning that they attract non-polar liquids including most oils, while rejecting polar solvents including water. However, MBPP sorbents can also be modified to attract both polar and non-polar liquids, often called “universal” sorbents. For example, MBPP sorbents can be made to attract oil and water by adding a surfactant during the manufacturing process. Thus, MBPP is a particularly versatile sorbent material.
However, during use, sorbent products will reach a point of saturation which causes the sorbent material to become non-effective. Accordingly, the user of a sorbent product often must remove the sorbent product from the application or use site in order to ascertain whether the sorbent product has reached its saturation capacity. This process is inconvenient to the user and sometimes causes a delay in replacing the sorbent product even once it has passed its point of saturation. Additionally, this process increases costs associated with the sorbent product. Additional labor costs are necessary to remove, check, and replace a sorbent product that is less than fully saturated. Also, if the sorbent product is discarded prior to achieving full saturation, additional costs are incurred when putting into place new sorbent products prematurely.
U.S. Pat. No. 7,892,639 to Brady Worldwide, Inc., which is incorporated by reference herein in its entirety for all purposes, discloses an edge ingress label for attachment to a surface. This label includes one or more ink formulations which are dissolvable and dispersible within the label to visually indicate the presence of the solvent in the label.